Process for plasticizing fatty materials



y 5, 1969 c. E. MMICHAEL ET AL 3,455,700

PROCESS FOR PLASTICIZING FATTY ,MATERIALS Filed April 20. 1966 *A" van BNmrr "c" um-r FEED PUMP L UNE BQOSTER PUMP EL Inventor's Charles E .MMlchqel United States Patent PROCESS FOR PLASTICIZING FATTY MATERIALS Charles E. McMichael, Louisville, Ky., and William A.

Singleton, Pittsburgh, Pa., assignors to Chemetron Corporation, Chicago, 111., a corporation of Delaware Filed Apr. 20, 1966, Ser. No. 543,832 Int. Cl. A23d 5/02 U.S. Cl. 99-122 9 Claims ABSTRACT OF THE DISCLOSURE A process for preparing a plasticized fatty material which substantially reduces tempering times. A molten fat is cooled and partially crystallized at a first temperature in a first zone, then worked by agitation and partially crystallized at a second temperature higher than the first temperature in a second zone. Subsequently, the material is cooled and worked in a third zone at a temperature lower than the second temperature and at about the same or 'a lower temperature than in the first zone to form small and well distributed crystal nuclei in the beta prime form.

This invention relates to an improved process and apparatus for treating fatty materials and more particularly to a process and apparatus for manufacturing shortening material which obviates long tempering periods.

The most commercially accepted method for producing plastic shortening agents is to prepare a melted blend of desired fat materials, introduce an inert gas generally in an amount such that the finished product will contain l0 20% of finely dispersed gas, precool the mixture of fat and inert gas to a temperature close to the solidification point of the fat, rapidly and simultaneously agitate and supercool the mixture to below its normal solidification temperature and subsequently work by agitating the partially solidified mixture without additional cooling until crystallization approaches completion. The semi-plastic product is then passed through an extrusion valve, filled into containers and held in a quiescent state under a predetermined and controlled temperature of between about 75 85 F. until solidification is achieved. This final step is referred to as tempering.

Apparatus extensively employed for performing the above operations and manufactured by the Votator Division of Chemetron Corporation comprises a precooler, one or more externally chilled tubes (commonly referred to as A units) which are provided with internal rotating shafts fitted with scraper blades for removing the thin film of chilled material from the tube walls and one or more worker tubes (commonly referred to a B units) which are provided with internal rotating shafts fitted with spirally positioned pins for working by agitating the product as it further crystallizes. The foregoing procedure, as well as the referred to apparatus, are fully described on pages 1064-1068 of A. E. Baileys book Industrial Oil and Fat Products, 3rd edition (Interscience Publishers, Division of John Wiley & Sons). It should be noted that at lines 23-26 inclusive on page 1068 of Bailey that tempering times up to 72 hours are indicated to attain optimum consistency and creaming characteristics. T empering for periods in excess of 72 hours is practiced frequently.

Attempts to eliminate the tempering period are indicated in U.S. 3,117,011 wherein the fatty triglycerides are heated under quiescent conditions at a temperature in the range of 90-l10 F. Another approach at eliminating tempering periods is that taught in U.S. 3,006,770 where the A and B units are not employed and a fat is atomized in a molten state in a crystallization zone maintained under conditions of temperature so that a very fine mist of the molten fat is contacted with a cooling gaseous medium to cause crystallization of the fat or shortening composition without marked supercooling.

As previously stated, the vast majority of shortening produced commercially at present employs the A and B units and as indicated in US. 3,117,011 the shortening industry has always deemed it necessary to keep a shortening product previously process in an A and B unit in a quiescent state and at a controlled temperature once it leaves the B unit in order to produce a commercially acceptable shortening product having the desired consistency or plasticity. Other methods of treating fats which do not employ the A and B units have not met with commercial acceptance.

It is an object of the present invention to provide an improved method of preparing a plasticized fatty material. It is another object of this invention to provide a process for preparing a plasticized fatty material. It is another object of this invention to provide a process for preparing a plasticized shortening which eliminates long tempering times and large storage rooms. It is still anotherobject of the present invention to provide a process for preparing a shortening material which employs a minimum number of steps and with apparatus which is presently commercially available. These and other objects of the present invention will be apparent from the following detailed description, and the drawing, in which:

FIGURE 1 is a flow diagram of the process and apparatus of the present invention.

FIGURE 2 is a view in vertical section showing somewhat schematically the internal construction of a preferred form of the heat exchange unit, having a concentrically positioned rotating shaft.

FIGURE 3 is a view like FIGURE 1 of the preferred worker unit.

FIGURE 4 is also a view in vertical section showing somewhat schematically the internal construction of a preferred form of another heat exchange unit, having an eccentrically positioned rotating shaft.

In a preferred embodiment of the invention, illustrated in FIGURES 1-4, a molten fat is introduced under pressure by means of feed pump 11 and conduit 12 into a standard A unit 14 wherein the fat is partially crystallized and passed into the B unit 15 by means of conduit 16. After working by agitation in unit 15, the fat is conveyed through conduit 18 through a C unit 20, wherein it is further worked and cooled and subsequently fed through an extrusion valve 22 to a fill line by means of conduits 23 and 24, the necessary pressure or force being provided by booster pump 25.

As previously indicated, units 14 and 15 are standard equipment, and unit 20 is a commercially available apparatus which is described in a U.S. patent application filed Feb. 4, 1965, Ser. No. 432,447, now U.S. 3,385,354 by Henry W. Bevarly, and assigned to Chemetron Corporation. All of the equipment, being adequately described in publications, only a brief description will be given herein. Referring to the heat exchange unit, generally 14, a pair of generally circular end plates 30 and 31 are recessed to receive the ends of the heat transfer tube 33. Ring members 34 are sleeved on tube 33 adjacent to the end plates and support a pair of cylindrical elements 36 and 37 to provide an annular space 38 for heat transfer fluid around tube 33. The space between the elements is filled with insulation 39 to provide an insulating jacket. A rotatable shaft 40 is journaled in end plates 30 and 31 and disposed concentrically within tube 33, filling a major portion of the space within the tube and forming an elongated annular passage 41 for the shortening material. Shaft 40 carries a plurality of blades or scrapers 42 to prevent sticking of the material to the inner surface of tube 33. A suitable drive mechanism (not shown) is provided to rotate the shaft at the desired speed. Shortening material enters unit 14 through inlet conduit 43 and leaves through outlet conduit 44 at the opposite end. Heat transfer fluid is conducted to and from the annular space 38 by connections 46 and 47.

Unit 20, like unit 14, also comprises a pair of generally circular end plates 50 and 51, recessed to support the ends of heat transfer tube 53. Ring members 54 and 55 are sleeved on tube 53 and support a pair of cylindrical elements 56 and 57 to provide an annular space 58 for heat transfer fluid around tube 53. The space between the elements is filled with insulation 60. Shortening material enters unit 20 through inlet conduit 61 at one end and leaves through outlet conduit 62 at the opposite end. Heat transfer fluid is conducted to and from annular space 58 by connections 64 and 65. A major and substantial difference between units 14 and 20 is in the positioning of rotating mutator shaft 66, the axis of the shaft being offset, or eccentric with tube 53, so that the shaft is nearer the heat exchanger surface in one transverse section than in other sections. This is accomplished by having shaft 66 journaled in end plates 50 and 51 in an eccentric manner. A plurality of blades 67 are hingedly attached to shaft 66 to provide contact at all times with the inner surface of tube 53 and a position around the shaft to aid in the movement of shortening material through the ever changing dimensions of the passage between shaft 66 and tube 53 as shaft is rotated by a drive means (not shown). In unit 20, on rotation around the shaft, a representative particle of material will be subjected to the rotational force of a large number of revolving blades. It will also be subjected to increasing pressures followed by decreas ing pressures as the material escapes from the high pressure zone, as by moving forward or backward longitudinally or as by escaping around the moving blades in a direction counter to the direction of the blades and shaft to reach a lower pressure zone behind the blades. Further, a representative particle will move inwardly and outwardly from the rotating shaft as pressures and velocities vary. While the off-center shaft heat exchanger is the preferred apparatus, other apparatus capable of simultaneously cooling and working a semi-plastic material may be employed, such as the heat exchanger and mixer apparatus described in US. Patent No. 3,235,002 by Bevarly et al. which is also assigned to Chemetron Corporation. The apparatus of Bevarly et al. also has an off-center type shaft in a tubular heat exchanger. However, while one end of the shaft is eccentric with respect to the centerline of the heat transfer tube, the other is concentric. The eccentricity of the shaft is essential to impart sufficient and desired working or kneading to the plasticized mass and still prevent a mere rotation of the material within the tubular scraped surface heat exchanger.

Unit 15, unlike units 14 and 20, has no heat exchange means, but it does have the usual cylindrical tube 70 mounted by means of end plates 71 and 72. Thorough mixing with low shear is accomplished by a. series of pins 73, arranged in a helical pattern on shaft 75, which cooperate with a row of similar stationary pins 76 mounted in the wall of tube 70. Shaft 75 is rotated by drive means (not shown) and product enters by connection 78 and leaves by connection 79 in the respective end plates.

The preferred temperature ranges for the present process are 60 F. to 80 F. in the first zone represented by the A unit; 75 to 85 F. in the second zone represented by the B unit and 55 to 75 F. in the third zone created by the previously described off-center shaft apparatus referred to herein as the C unit. The temperature ranges in the first and second zones are those normally employed for a specific shortening product being processed by the conventional method. Best results as far as product quality and elimination of tempering are concerned, are achieved when the temperature in the third zone is equivalent to or slightly below the temperature of the product as it is discharged from the first zone. The processed product is filled in suitable containers such as 50 pound or larger containers by standard methods at a preferable temperature in the range of -85 F.

Shortening which may be treated by the method of this invention include both blended and all hydrogenated types prepared from animal or vegetable fats, mixtures thereof, as well as the emulsified and standard all-purpose household shortening. The typical shortening should have a Wiley melting point in the range of about 102l20 F. Solid fat indices for typical shortenings at 50 F. range from 20 to 60. The unsaturated hydrogenated shortenings which can be processed by this invention have iodine values from about 65 to about 85.

Irrespective of the type of shortening employed it has been found that the consistency of the shortening prepared in accordance with the present invention reached equilibrium in much shorter time when employing the C unit. In most instances equilibrium is reached within eight hours after filling from the C unit, whereas it required four days for the same shortening to do so when processed in the conventional manner.

The invention is disclosed in further detail by means of'the following examples which are set forth for the purpose of illustrating the invention, but in no way are to be construed as limiting the invention in spirit or scope.

EXAMPLE I A typical high ratio type shortening was selected having the following general characteristics:

Composition Hydrogenated vegetable oil. Color 6y0.6 red.

Free fatty acids 0.05 %0.06%.

Wiley melting point 116.0 F.-117.8 F.

Monoglycerides (alpha) 3.5%3.6%. Solid fat index at- 50 F. 23.4-25.7. F 17.719.9. 92 F. 12.7-14.4.

The foregoing described shortening at a temperature of l30l40 F. was pumped at a throughput rate of about 7500 lbs/hr. from a suitable supply tank to a standard precooler where it was cooled to a temperature of about'1l0-115 F. and then entered the Votator A unit assembly. The product was chilled to 70 F. in the A unit and discharged from the B unit at F. The product was transferred from the B unit at a temperature of 80 F. and cooled in the off-center shaft Votator C unit to a temperature of 68 F. From the C unit the chilled product was pumped by means of a standard gear type booster pump through an extrusion valve to a standard filling machine where the product was filled in 50 pound containers at a temperature of 73 F.

The consistency of the product as processed in this example reached equilibrium within eight hours after filling. The same shortening, when proscessed in a system employing only the conventional A and B units, required processed in the indicated conventional manner. The results are shown in Table I below wherein column B represents a shortening made by the conventional system employing only A and B units.

EXAMPLE II Employing the same shorteningmaterial set forth in Example I and the general procedure outlined therein, Table 11 below illustrates runs made under various conditions of processing as well as performance results. 5

TABLE 11 Run No 1 2 a 4 5 Temperature from A unit (deg.) 69 68 69 69 69 Temperature from B unit (deg.) 83 Temperature from C unit (deg.) 69 Temperature from booster pmnp 73 Temp. from 2nd B unit Temperature at filler 83 84 77 Pressure (p.s.i.g.) 500 500 500 Rate (lbs. per hour) 7, 800 7, 800 7, 800 24 hours after filling cream icing, sp. gr.

at min 0. 76 0. 76 0. 75

0.79 0.83 0.83 1, 230 1, 160 1, 190 10 days after filling pound cake:

Batter, sp. gr 0. 82 Cake volume, cc./lb 1, 220

Runs 4 and 5 represent conventional processing without the C unit, while Run 1 employing the C unit shows that the pound cakes were just as good when made with shortening 24 hours after packing as they were 10 days after packing. Runs 4 and 5 did not produce as good pound cake as Run 1 either after 25 hours or 10 days.

No significant improvement is shown, as measured by pound cakes, when the second B unit was used as shown in Run 2.

There appears to be no significant advantage in using a C unit for the production of shortening to be used for making cream icings, but as the same shortening is frequently used for pound cakes, white layer cakes, and cream icing, it is an advantage to make such shortenings with the C unit employed.

It will be noted that a-booster pump of a standard gear type was used in Runs 1 and 2 and that an additional B unit was used in Run 2. It is known that with conventional operation, using only the A and B units, the super cooled product leaving the A and B units is still 25 ing of Runs 4 and 5, but inferior to the product obtained content is below the equilibrium Solid Fat Index (SFI) in Runs 1 and 3 Where the additional B unit was not employed.

EXAMPLE III An average high ratio type shortening was selected having the following characteristics:

Free fatty acids (as oleic) percent 0.05 Wiley melting point F 116.0 Iodine value 81.8 Monoglycerides (alpha) percent 3.6 S.F.I. at

This material was prepared employing the general procedure outlined in Example I under the conditions described in the following Table III which also illustrates performance results.

TABLE III Run No 1 2 3 4 5 Temperature fromdA unit F.). 70 70 70 70 70 Temperature from B unit (deg). 80 80 78 79 80 Temperature from "0 unit (deg.) 60 65 60 Temperature from 2nd B unit (deg.) 68 64 Temperature from booster pump (deg) 64 72 68 Temperature at filler (deg) 73 76 72 78 Temperature extrusion at filler 500 500 500 500 500 Product rate, lbs/hr 7, 500 7, 500 7, 500 7, 500 7, 500 Within 8 hours after pack.:

Pound cake batter, sp. gr 0.85 0. 83 0.85 0.82 0. 83

Cake volume, cc./lb 1, 175 1, 220 1, 1, 1, 140 24 hours after paek.:

Batter, sp. gr 0. 79 0.79 0. 82 0. 86 0.82

Cake volume, cc./lb 1, 200 1, 200 1, 1, 140 1, 150

for the product at the processing temperature. When the off-center shaft C unit is used following the A and B units it is necessary to operate at a much higher extrusion pressure at the filler of about 500 pounds/square inch for the proper fill as the product is much firmer indicating that the actual solid fat content approaches the equilibrium SFI of the product at the processing temperature. The use of a booster pump is preferred in actual practice to avoid excessive pressures within the preceding items of apparatus. As additional work is imparted to the product in passing through the booster pump, a second 75 tained.

7 EXAMPLE IV An all-purpose, non-emulsified shortening was selected having the following characteristics:

The foregoing described shortening was heated to 135140 F. in a suitable supply tank from which it entered the concentric shaft Votator A unit within the same temperature range. The product was chilled to 69 F. in

the A unit and discharged from the B unit at 78 F. The

product was transferred from the B unit and processed in the oif-center shaft Votator C unit at a temperature of 70 F. From the C unit the chilled product was pumped by a gear type booster pump to a pressure of 300 p.s.i.g. to a standard filling station where the product was filled into fifty pound containers at a temperature of 78 F. The product rate through the A, B and C units was 8,000 pounds per hour.

Baking tests in pound cake were made on the shortening product twenty hours after packing with the results illustrated in Table V.

Another all-purpose, non-emulsified shortening was selected having the following characteristics:

Color 5y-0.5 red Free fatty acid percent 0.02 Wiley melting point F 115.4 S.F.I. at

50 F. 25.0 70 F. 19.8 92 F. 13.5 104 F. 8.9

The same general procedure as outlined in Example IV was followed employing the data in Table V below which also illustrates performance results.

standard recipes as indicated from the following ingredients:

POUND CAKE Amounts Ingredients Lbs. Ozs

Shortening 1 7 Granulated sugar... 2 v 7 Salt 0 1 2 0 Liquid milk 1 0 Vanilla 0 Whole eggs 1 7 C BEAM 10 IN G Amounts Ingredients Lbs. Ozs

Powder sugar 6X 3 0 Shortening 0 14 Powder skim milk 0 3 Salt 0 A Vanilla 0 3/; Water 0 8 Table V Designation: Amount Temperature from A Unit F 66 Temperature from B Unit F 81 Temperature from C Unit F 68 Temperature at filler F..- 78 Pressure at filler p.s.i.g. 300 Rate in pounds per hour 8000 a 20 hours after filling:

Pound cake batter (sp. gr.) 0.85 Batter temperature F 75 Cake volume cc./lb 1060 The shortenings of Examples IV and V show normal texture and performance within 24 hours after packing, comparable to the results obtained with conventionally processed non-emulsified shortenings.

The pound cakes and cream icings employed in the performance tests in Examples I-V are prepared from Both recipes were prepared in the same manner for the conventionally processed shortening and for the shortening according to the process of this invention. As such preparations are familiar to those skilled in the baking and pastry art they are not set forth.

While the phenomena associated with tempering of shortenings by any method is not clearly understood, it is known that the end result is the formation of a stable crystalline mass with the preponderance of crystals existing in the beta prime form for most products. It is believed that the further chilling operation with concurrent working of the product as taught by this invention with reduction of the product temperature to about the same or slightly lower temperature of the first chilling operation, results in the formation of additional small crystal nuclei and yields a saturated crystalline mass with uniform crystal distribution in essentially a state of equilibrium.

The examples of this invention illustrate that the use of the A, B and C units produce a shortening material that is equivalent and even more generally superior to shortenings produced by conventional methods. The examples further show that such shortening materials do not require the long tempering periods as do conventionally processed shortenings. Further evidence of a well tempered product and one exhibiting smaller and more uniformly distributed crystals has been noted through crystallographic studies. Small and uniform crystal structures enhance a fats aerating properties which are so important in the preparation of toppings and particularly in cakes where high volumes and even texture are desired.

We claim:

1. A process for preparing a plasticized fatty material wherein the formerly required tempering time is substantially reduced comprising the steps of cooling and partially crystallizing a molten fat in a first zone and at a first temperature, working by agitation said partially crystallized fat at a second temperature and higher than said first temperature to further promote the formation of many small crystals and a plasticized fatty material in a second zone and further cooling and working said fatty partially crystallized material at a temperature lower than said second temperature and at about the same or a lower temperature than in said first zone to form additional small and well distributed crystal nuclei and effect subterial is a plastic shortening preparation.

3. A process for preparing a plasticized fatty material as defined in claim 1 wherein said fatty material contains an emulsifier.

4. A process for preparing a plasticized fatty material as defined in claim 1 wherein said fatty material is of the nonemulsified type.

5. A process for preparing a plasticized fatty material as defined in claim 1 wherein said plasticized fatty material is cooled and worked in said third zone in said range of about 55 F. to about 75 F. by applying a rotational component of movement to said material within a tubular heat exchanger.

6. A process for preparing a plasticized fatty material as defined in claim 4 wherein said fatty material in said third zone when subjected to said rotational component in said heat exchanger is simultaneously subjected to a series of intermittent pressure pulsations and the material is moved in a slow spiral motion while being moved in a series of intermittent longitudinal backward and forward motions.

7. A process for preparing a plasticized fatty material as defined in claim 1 wherein the temperature in said first zone is in the range of about 60 F. to about 80 F., the temperature in said second zone is in the range of about 75 F. to about 85 F. and the temperature in the third zone is in the range of about 55 F. to about 75 F.

8. A process for preparing .a plasticized fatty material as defined in claim '1 wherein said plasticized fatty material is cooled and worked in said first zone by applying a rotational component of movement to said material within a tubular heat exchanger and said fatty material in said third zone is subjected to a rotational component in a heat exchanger and simultaneously subjected to a series of intermittent pressure pulsations and the material is moved in a low spiral motion while being moved in a series of intermittent longitudinally backward and forward motions.

9. A process for preparing a plasticized fatty material as defined in claim 1 further including a filling zone wherein the temperature is in the range of about F. to about F.

References Cited UNITED STATES PATENTS 2,063,066 12/1936 Vogt 62--69 3,019,110 1/1962 Bevarly 99-422 3,095,305 6/ 1963 Kearns 99-118 MAURICE W. GREENSTEIN, Primary Examiner US. Cl. X.R.

Patent No.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Dated July 15, 1969 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2,

Column 2,

Column 8,

(S Atteat:

line 8, processed should be read for "process" lines 17 and 18 "It is another object of this invention to provide a process for preparing a plasticized fatty material." should be deleted. Column 5,

line 30, 24 should be read for "25" line 56, insert the following paragraph It will thus be seen that there is now provided a process for producing a shortening material which has all of the characteristics of a product which formerly required a tempering period of from 24-240 hours. Large tempering storage rooms are no longer required and the product can be shipped directly from the filling apparatus. A substantial reduction in handling and storage is thereby effected resulting in a reduction in production costs smcb mu snuzn APR 2 a 1970 EdwardlLFletcherJr.

Attesting Officer WILLIAM E. 'SGHUYIIER. JR. Commissioner of Patents 

